Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042961 (volvulus)
 4,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanism by which filarial parasites derive fatty acids bound to the host's carrier protein is poorly understood. The capacity of a secretory protein of Onchocerca volvulus (OvS1/Ov20) to compete with serum albumin for arachidonic and other fatty acids was investigated in this study. Binding affinities of the two proteins for the long-chain fatty acids were determined using displacement assays. The fluorescent probes used included 11-((5-dimethylaminonaphthalene-1-sulfonyl)amino) undecanoic acid (DAUDA) and cis-parinaric acid. OvS1 protein bound arachidonic acid with an affinity five-fold greater than the affinity exhibited by serum albumin. Oleic acid was bound by the parasite protein with an affinity two-fold greater than the affinity shown by serum albumin. Furthermore, the affinities exhibited by OvS1 protein in binding arachidonic and linoleic acid were about two times higher than the affinity for oleic acid. The results suggest that the OvS1 protein has the capacity to compete with the main host's fatty acid carrier protein for the long-chain fatty acids, in particular arachidonic acid, the precursor for eicosanoids.
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PMID:The secretory Onchocerca volvulus protein OvS1/Ov20 exhibits the capacity to compete with serum albumin for the host's long-chain fatty acids. 1069 49

The Onchocerca volvulus secretory protein Ov20/OvS1 represents a dominant antigen expressed in the infective larvae, microfilariae and adult stages of the parasite. The humoral responses to this protein have not yet been analysed in the polar clinical and immunological forms of onchocerciasis. Analysis by ELISA of class and subclass antibodies to Ov20/OvS1 in persons with the generalized or the hyperreactive form of onchocerciasis revealed similar strong responses of IgG1, IgG4 and IgM antibody levels in both forms of onchocerciasis and significant differences were observed in the IgE and IgA antibody classes. Computation of the ratios of antibodies showed that persons with the generalized form exhibited significantly higher ratios of IgG4 to IgG1, IgG4 to IgE, and IgM to IgE than patients with the hyperreactive form. To investigate the isotype recognition of antigenic sites on Ov20/OvS1 protein, three recombinantly expressed fragments (F1-3) of Ov20/OvS1 were probed using sera which strongly reacted with intact recombinant Ov20/OvS1. Epitope(s) on F1 comprising amino acid residues 1-63 were significantly recognized by IgG1 and IgE, while IgM recognized epitopes on all three fragments. The strongest reaction of IgM occurred with epitope(s) formed by residues 108-171 (F3). In contrast, IgG4 type antibodies were not reactive with either of the three OvS1 fragments, but they reacted with intact Ov20/OvS1 protein. Generalized onchocerciasis, unable to eliminate microfilariae, and hyperreactive onchocerciasis, with a high potency to eliminate or to reduce parasite loads, can be distinguished by a distinct pattern of isotype responses to Ov20/OvS1.
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PMID:Humoral responses to a secretory Onchocerca volvulus protein: differences in the pattern of antibody isotypes to recombinant Ov20/OvS1 in generalized and hyperreactive onchocerciasis. 1097 52